Homeland Security Preparedness: Balancing Protection with Resilience in Emergent Systems

The report of the President's Commission on Critical Infrastructure Protection IPCCIP, Executive Order 13010, The White House, Washington, DC, 19971 which was issued in October 1997 set in motion a revolutionary and expensive national homeland security initiative under the rubric of critical infrastructure protection. The PCCIP addressed a plethora of sources of risk to the nation's critical infrastructures, along with numerous risk management options. For simplicity, we partition solution possibilities into two major types: protecting system assets and adding resilience to systems. Much of government research efforts focus on analyzing component systems and their assets. Systems engineers are particularly interested in characteristics that emerge from the system design, which are affected by changes to component systems, but also by changes that reflect the way systems are constructed and integrated. Adding resilience to a system expands the focus beyond component systems to include a study of emergent, system-level attributes for homeland security consideration. Balancing protective and resilience actions through system-level analysis will provide a means to improve the overall efficiency of regional and national preparedness. This paper explores concepts of emergence, resilience, and preparedness as a foundation for establishing a framework to assess the balance between the two areas of infrastructure risk mitigation. We propose several considerations that must be included in a framework to assess protection and resilience tradeoffs, and we present a simple illustrative study that demonstrates several of the framework concepts and provides a means for further discussion about the complex interactions that are faced when evaluating the resilience of a system. (C) 2008 Wiley Periodicals, Inc. Syst Eng 11: 287-308, 2008